A city neighboring Ferguson, Mo., has agreed to pay $4.7 million to an estimated 2,000 mostly poor, black residents it jailed for unpaid court debts, many of them for minor offenses such as traffic tickets.

The agreement comes in a proposed settlement of a class-action lawsuit preliminarily approved by a federal judge in Missouri on Wednesday.

The deal with Jennings, Mo., would mark the highest daily rate of compensation reached in a settlement with a U.S. municipality to resolve incarceration practices of this kind, according to civil rights lawyers who brought the case.

Critics of the jailings argued that they criminalize poverty and called the detentions unconstitutional because of a prohibition against jailing people just because they are too poor to pay.

Attorneys for the city reached “a comprehensive settlement that hopefully can be a model for other jurisdictions employing debtors’ prisons and cash bail” pending final approval by the court, said Thomas B. Harvey, executive director of ArchCity Defenders of St. Louis, which represented eight lead plaintiffs with lawyers from the Saint Louis University School of Law and Washington-based Equal Justice Under Law.

However, Harvey added that “there are 90 cities surrounding Jennings and Ferguson. Until all of them change their practices either voluntarily or as the result of legislation or litigation . . . this is still going to be a region that over-polices for revenue and criminalizes black life.”

D. Keith Henson, a lawyer representing the city of about 14,700 residents, said it will have no comment before final approval of the settlement, which includes an additional $1 million to $2 million in debt forgiveness for those detained for nonpayment in the city’s jail between Feb. 8, 2010, and Sept. 16, 2015.

U.S. District Judge Carol E. Jackson of the Eastern District of Missouri set a hearing for Dec. 14.

The legal groups filed lawsuits in February 2015 against Jennings and Ferguson, alleging that the cities increasingly saddled poor and black defendants with a disproportionate share of the costs of the local criminal justice system, fueling the type of frustrations that erupted after the fatal police shooting in 2014 of Michael Brown in Ferguson.

Ferguson has adopted its own reforms but not settled its case after mediation, with a trial tentatively set for next July. Ferguson attorney Robert T. Plunkert with Pitzer Snodgrass of St. Louis declined to comment, citing pending litigation.

The Justice Department in March wrote local courts in all 50 states to warn them that raising revenue through fines and fees that exposed poor people to escalating debt and were enforced through jail time or driver’s license suspensions, for example, often violated constitutional protections.

About 81 of 90 municipalities near St. Louis run decentralized local courts, which with St. Louis County collected nearly half of $132 million in fines paid by Missourians, a 2014 study found, despite the area being home to fewer than one in four state residents.

More than a dozen small towns that, like Ferguson and Jennings, have large black populations reaped more from traffic-court fees and fines than from sales taxes or property taxes, the study found. People who do not pay the penalties often are arrested. Revenue often stemmed from violations such as driving with a suspended license, expired registration or no proof of insurance.

Jennings in September consented to a federal court order dismissing “failure to appear” charges, ending cash bail for nonviolent offenses, and offering the indigent waived or reduced fines or community-service alternatives. The city agreed to release people on first arrest and to rely on civil debt collectors.

Area localities at that time also agreed to lift tens of thousands of driver’s license suspensions based on a person’s failure to appear in court. Ferguson also has capped court revenue at 15 percent of the city budget, abolished the “failure to appear” offense and related fines, withdrawn 10,000 warrants issued before 2015, and eliminated fees to tow vehicles and revoke warrants.